Mr. Yoshiaki Sato, the present inventor, has conducted studies for quite some time in order to develop a muscle strength increasing method for easy, safe, and effective muscle development, and put together the accomplishments into a patent application having Japanese Patent Application No. 5-313949, which has been granted as Japanese Patent No. 2670421.
The muscle strength increasing method according to the subject patent, which involves the application of pressure, is a distinctive non-conventional one. This muscle strength increasing method (hereinafter, referred to as “KAATSU training (registered trademark) method”) is based on the following theoretical concept.
Muscles are composed of slow-twitch muscle fibers and fast-twitch muscle fibers. Slow-twitch muscle fibers are limited in their potential for growth. Accordingly, it is necessary to recruit fast-twitch muscle fibers of the slow- and fast-twitch muscle fibers in order to develop muscles. Recruitment of fast-twitch muscle fibers causes lactic acid buildup in the muscles, which triggers secretion of growth hormone from the pituitary. The growth hormone has effects of, for example, promoting muscle growth and shedding body fat. This means that recruitment and exhaustion of fast-twitch muscle fibers results in development of fast-twitch muscle fibers and, in turn, the entire muscles.
Slow-twitch muscle fibers and fast-twitch muscle fibers are different from each other in terms of the following. Slow-twitch muscle fibers use oxygen for energy and are recruited for low-intensity activities. Fast-twitch muscle fibers provide for activities regardless of whether or not oxygen is present. They are recruited after the slow-twitch muscle fibers for highly intense activities. Therefore, it is necessary to cause the earlier recruited and activated slow-twitch muscle fibers to be exhausted soon in order to recruit fast-twitch muscle fibers.
Conventional muscle strength increasing methods use heavy exercises with, for example, a barbell to cause the slow-twitch muscle fibers to be exhausted first, and then to recruit the fast-twitch muscle fibers. This recruitment of fast-twitch muscle fibers requires a significant amount of exercises, is time-consuming, and tends to increase the burden on muscles and joints.
On the other hand, muscle exercise may be performed under the condition of restricted blood flow into the limb distal to a predetermined location by means of applying pressure upon the muscles at the predetermined location near the top of the limb. Since less oxygen is supplied to these muscles, the slow-twitch muscle fibers, which require oxygen for energy, are thus exhausted in a short period of time. Muscle exercises with blood-flow restriction by application of pressure will result in recruitment of the fast-twitch muscle fibers without needing a large amount of exercises. More specifically, when a predetermined region near the top of a limb is compressed with pressure, venous circulation is restricted while arterial circulation is almost the same as the normal condition if an appropriate pressure is applied. This is because veins are closer to the skin surface of the limb while arteries are found deep within the limb. By holding that condition for a certain period of time, the limb that has compressed near the top thereof becomes engorged with blood which runs from arteries but cannot flow through veins. This condition is very close to the one achieved during heavy exercise of that limb. Consequently, the muscles get extremely exhausted. In addition, the muscle fatigue is also caused by the fact that the lactic acid that has built up in the muscles is less likely to be removed from the muscles because of the temporal occlusion of the veins.
A KAATSU training method can artificially provide a condition as described above that is similar to conditions obtained during and after exercises. This means that the KAATSU training method provides effects of muscle training and promotes secretion of growth hormone.
Based on the aforementioned mechanism, restriction of muscle blood flow can provide significant development of the muscles.
The KAATSU training method is premised on theoretical concept of muscle strength increase by the restriction of blood flow. More specifically, the KAATSU training method is intended to apply an appropriate compression force upon at least one of the limbs at a predetermined location near the top thereof, for the blood flow restriction into the limb distal to that location; put an appropriate stress attributed to blood flow decrease on the muscles, by the compression force; and thereby cause muscle fatigue. Thus, effective muscle development is achieved.
The KAATSU training method can compensate for a total amount of stress that is placed on the muscles by putting on the muscles a stress attributed to blood flow decrease. When combined with some exercises, the method advantageously reduces an exercise-related load as compared with conventional methods. This feature produces effects of reducing possible risks of joint- or muscle-damages and shortening a necessary time period for training, because it can decrease the amount of muscle exercises for the muscle development.
In addition, the KAATSU training method features muscle development without any exercises because it involves developing muscles by putting a stress attributed to blood flow decrease on the muscles. With this feature, the KAATSU training method is highly effective for the muscle development or for the recovery of motor ability in people with impaired motor function, e.g., the elders or an injured person.
When the KAATSU training is performed, it is very important how strong the proximal portion of the arm or the leg of the user is to be compressed.
The KAATSU training can achieve its effect only if it artificially provides conditions as if the arm or the leg of the user were doing heavy exercises, with blood-flow restriction by application of pressure to a proximal portion of the arm or the leg of the user. On the other hand, the KAATSU training can endanger the health of the user if the blood flow is excessively restricted.
However, at present, how large of a force is used to compress the arm or leg of the user is often determined by the person, relying on his or her knowledge and experience of the KAATSU training.
The present invention is directed to solve such problems and an object thereof is to provide a technique with which the KAATSU training can be used effectively, safely, and easily even by a person who has little skill of it.